Dynamical rheology of a lyotropic lamellar phase near an out-of-equilibrium transition

2004 ◽  
pp. 121-123
Author(s):  
J. -B. Salmon ◽  
A. Colin ◽  
S. Manneville ◽  
D. Roux
Keyword(s):  
Lamellar Phase ◽  
Equilibrium Transition

scholarly journals Inclusion of Laponite nanoparticles in a lyotropic lamellar phase

2021 ◽  
Vol 47 (1) ◽  
pp. 49-59
Author(s):  
Girlane Castro Costa Leite ◽  
Gilson Carlos Castro Costa Leite
Keyword(s):  
Lamellar Phase

scholarly journals Exploring the in meso crystallization mechanism by characterizing the lipid mesophase microenvironment during the growth of single transmembrane α-helical peptide crystals

2016 ◽  
Vol 374 (2072) ◽  
pp. 20150125 ◽  
Author(s):  
Leonie van 't Hag ◽  
Konstantin Knoblich ◽  
Shane A. Seabrook ◽  
Nigel M. Kirby ◽  
Stephen T. Mudie ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Self Assembly ◽  
Lamellar Phase ◽  
Cubic Phase ◽  
Supporting Evidence ◽  
X Ray ◽  
X Ray Scattering ◽  
Standard Procedures ◽  
Helical Peptide ◽  
Saxs Analysis

The proposed mechanism for in meso crystallization of transmembrane proteins suggests that a protein or peptide is initially uniformly dispersed in the lipid self-assembly cubic phase but that crystals grow from a local lamellar phase, which acts as a conduit between the crystal and the bulk cubic phase. However, there is very limited experimental evidence for this theory. We have developed protocols to investigate the lipid mesophase microenvironment during crystal growth using standard procedures readily available in crystallography laboratories. This technique was used to characterize the microenvironment during crystal growth of the DAP12-TM peptide using synchrotron small angle X-ray scattering (SAXS) with a micro-sized X-ray beam. Crystal growth was found to occur from the gyroid cubic mesophase. For one in four crystals, a highly oriented local lamellar phase was observed, providing supporting evidence for the proposed mechanism for in meso crystallization. A new observation of this study was that we can differentiate diffraction peaks from crystals grown in meso , from peaks originating from the surrounding lipid matrix, potentially opening up the possibility of high-throughput SAXS analysis of in meso grown crystals. This article is part of the themed issue ‘Soft interfacial materials: from fundamentals to formulation’.

Noncentrosymmetric Lamellar Phase in ABCD Tetrablock Copolymers

2004 ◽  
Vol 37 (18) ◽  
pp. 7042-7050 ◽  
Author(s):  
Karim M. Jaffer ◽  
Robert A. Wickham ◽  
An-Chang Shi
Keyword(s):  
Lamellar Phase

scholarly journals Bending elastic properties of a block copolymer-rich lamellar phase doped by a surfactant: a neutron spin-echo study

Soft Matter ◽  
2014 ◽  
Vol 10 (36) ◽  
pp. 6926-6930 ◽  
Author(s):  
H. Egger ◽  
G. H. Findenegg ◽  
O. Holderer ◽  
R. Biehl ◽  
M. Monkenbusch ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Elastic Properties ◽  
Spin Echo ◽  
Lamellar Phase ◽  
Neutron Spin ◽  
Neutron Spin Echo

scholarly journals Dissociation, unfolding and refolding trials of pig kidney 3,4-dihydroxyphenylalanine (dopa) decarboxylase

1993 ◽  
Vol 295 (2) ◽  
pp. 493-500 ◽  
Author(s):  
P Dominici ◽  
P S Moore ◽  
C Borri Voltattorni
Keyword(s):  
Conformational Changes ◽  
Dopa Decarboxylase ◽  
Experimental Conditions ◽  
High Tendency ◽  
Denatured Protein ◽  
Pig Kidney ◽  
Plausible Model ◽  
Spectroscopic Characteristics ◽  
Equilibrium Transition ◽  
Almost All

The effect of guanidinium chloride (GuCl) on enzyme activity, hydrodynamic volume, circular dichroism, and fluorescence of 3,4-dihydroxyphenylalanine (Dopa) decarboxylase from pig kidney (pkDDC) was studied under equilibrium conditions. Unfolding proceeds in at least three stages. The first transition, occurring between 0 and 1 M GuCl, gives rise to a dimeric inactive species which has lost pyridoxal 5′-phosphate (PLP), and has a high tendency to aggregate, but retains almost all of the native spectroscopic characteristics. The second equilibrium transition, between 1 and 2.2 M GuCl, involves dimer dissociation, with some loss of tertiary and secondary structure. Additionally, gross conformational changes at or near the PLP microenvironment were detected by fluorescence of NaBH4-reduced enzyme. The third step, presumably representing complete unfolding of pkDDC, appears to be complete at 4.5 M GuCl, as indicated by the lack of further substantial changes in any of the signals being studied. Attempts at refolding resulted in the findings that: (1) partial reactivation is observed only starting from enzyme denatured at concentrations below 1.5 M GuCl, and (2) starting from completely denatured protein, the refolding process is apparently reversible down to concentrations of approx. 2 M GuCl. Taken together, this would seem to indicate that the monomer-dimer transition is impaired under the experimental conditions tested. A plausible model is presented for the unfolding/refolding of pkDDC.

A Defective Lamellar Phase in a Nonionic Surfactant Water System Studied by NMR Methods

2003 ◽  
Vol 398 (1) ◽  
pp. 157-167 ◽  
Author(s):  
Luigi Coppola ◽  
Raffaella Gianferri ◽  
Isabella Nicotera ◽  
Cesare Oliviero
Keyword(s):  
Nonionic Surfactant ◽  
Water System ◽  
Lamellar Phase ◽  
Nmr Methods

Two Types of Lamellar Phase in TTAB/Water/Pentanol System as Detected by Positron Lifetime Spectroscopy

2004 ◽  
Vol 445-446 ◽  
pp. 316-318
Author(s):  
P.H. Khani ◽  
R. Yadav ◽  
K. Chandramani Singh ◽  
P.C. Jain
Keyword(s):  
Positron Lifetime ◽  
Lamellar Phase ◽  
Positron Lifetime Spectroscopy

Dopant-Mediated Interactions in a Lecithin Lamellar Phase

2008 ◽  
Vol 29 (7) ◽  
pp. 985-990 ◽  
Author(s):  
Luyan Wang ◽  
Xiao Chen ◽  
Zhenwen Sun ◽  
Yongcun Chai ◽  
Jingcheng Hao ◽  
...  
Keyword(s):  
Lamellar Phase

Shear-induced structural transition in a lyotropic lamellar phase studied using small angle neutron and light scattering

2005 ◽  
Vol 17 (31) ◽  
pp. S2923-S2928 ◽  
Author(s):  
T Kato ◽  
K Miyazaki ◽  
Y Kawabata ◽  
S Komura ◽  
M Fujii ◽  
...  
Keyword(s):  
Light Scattering ◽  
Small Angle ◽  
Structural Transition ◽  
Lamellar Phase
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